PLoS ONE (Jan 2020)

High expression of olfactomedin-4 is correlated with chemoresistance and poor prognosis in pancreatic cancer.

  • Ryotaro Ohkuma,
  • Erica Yada,
  • Shumpei Ishikawa,
  • Daisuke Komura,
  • Hidenobu Ishizaki,
  • Koji Tamada,
  • Yutaro Kubota,
  • Kazuyuki Hamada,
  • Hiroo Ishida,
  • Yuya Hirasawa,
  • Hirotsugu Ariizumi,
  • Etsuko Satoh,
  • Midori Shida,
  • Makoto Watanabe,
  • Rie Onoue,
  • Kiyohiro Ando,
  • Junji Tsurutani,
  • Kiyoshi Yoshimura,
  • Takehiko Yokobori,
  • Tetsuro Sasada,
  • Takeshi Aoki,
  • Masahiko Murakami,
  • Tomoko Norose,
  • Nobuyuki Ohike,
  • Masafumi Takimoto,
  • Masahiko Izumizaki,
  • Shinichi Kobayashi,
  • Takuya Tsunoda,
  • Satoshi Wada

DOI
https://doi.org/10.1371/journal.pone.0226707
Journal volume & issue
Vol. 15, no. 1
p. e0226707

Abstract

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Pancreatic cancer has an extremely poor prognosis, and identification of novel predictors of therapeutic efficacy and prognosis is urgently needed. Chemoresistance-related molecules are correlated with poor prognosis and may be effective targets for cancer treatment. Here, we aimed to identify novel molecules correlated with chemoresistance and poor prognosis in pancreatic cancer. We established 10 patient-derived xenograft (PDX) lines from patients with pancreatic cancer and performed next-generation sequencing (NGS) of tumor tissues from PDXs after treatment with standard drugs. We established a gene-transferred tumor cell line to express chemoresistance-related molecules and analyzed the chemoresistance of the established cell line against standard drugs. Finally, we performed immunohistochemical (IHC) analysis of chemoresistance-related molecules using 80 pancreatic cancer tissues. From NGS analysis, we identified olfactomedin-4 (OLFM4) as having high expression in the PDX group treated with anticancer drugs. In IHC analysis, OLFM4 expression was also high in PDXs administered anticancer drugs compared with that in untreated PDXs. Chemoresistance was observed by in vitro analysis of tumor cell lines with forced expression of OLFM4. In an assessment of tissue specimens from 80 patients with pancreatic cancer, Kaplan-Meier analysis showed that patients in the low OLFM4 expression group had a better survival rate than patients in the high OLFM4 expression group. Additionally, multivariate analysis showed that high expression of OLFM4 was an independent prognostic factor predicting poor outcomes. Overall, our study revealed that high expression of OLFM4 was involved in chemoresistance and was an independent prognostic factor in pancreatic cancer. OLFM4 may be a candidate therapeutic target in pancreatic cancer.